Heating pad



FIG. 1 is a front elevational view of a heating pad, showing my new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is bottom plan view thereof;

FIG. 5 is a right side elevational view thereof, the left side elevational view being substantially identical thereto; and,

FIG. 6 is an isometric view thereof. 

The ornamental design for a heating pad, as shown. 